The owls have not been seen on camera for a week and given the lateness in the season, I am not very confident they will return but I will keep watching. Many possibilities - she could have ended up choosing another nesting site, they did not mate to produce eggs, or one or both of them were injured or killed by predators. Sometimes if a female loses her mate during the brooding season, another male may try to provide for her even though he may already be in a mating pair. It takes a village.